The title silanates were extd. from grains, roots and stalks of 3 wheat species (Banti, Dada and Munk) in a Soxhlet app. with MeOH for 8 h. The silanates were adsorbed on a column filled with a phenylpropyl group-contg. stationary phase and eluted with MeOH. Content of the silanates was detd. in the eluents by capillary electrophoresis. The highest content of the silanates was detd. in wheat grains of Banti and Dada type (36.23 +/- 1.21 and 39.26 +/- 1.82 mu g/kg dry matter, resp.).